Decimals (Addition & Subtraction)：練習問題

A chef used \( 0.45 \) L of cooking oil on Monday. On Tuesday, he used \( 0.18 \) L more than he did on Monday. What was the total amount of oil used over the two days?

A rope was originally \(12.5\) meters long. \(3.75\) meters were cut from it. Later, a new piece of rope measuring \(6.8\) meters was tied to the remaining part.

What is the total length of the rope now?

In a race, Runner X finishes in \( 2.55 \) hours. Runner Y finishes \( 0.15 \) hours faster than Runner X. Runner Z finishes \( 0.4 \) hours slower than Runner Y. How many hours did it take for Runner Z to finish the race?

The first jug contains \( 2.45 \) L of water and the second jug contains \( 1.3 \) L of water. How much water is there in both jugs in total?

The total length of a hiking trail is \( 2.55 \) km. A hiker travels \( 0.8 \) km before his first break and another \( 1.15 \) km before his second break. How many kilometres are left to reach the end of the trail?

A bottle contains \(2.5\) L of milk. If Mrs. Lee uses \(0.85\) L for baking a cake, how much milk is remaining in the bottle?

A ribbon is \(5.25\) m long. A second ribbon is \(1.4\) m longer than the first one. What is the total length of the two ribbons combined?

Find the sum of \(14.6\) and \(7.58\).

Three siblings measured their heights for a school record. Ken is \(1.52\) metres tall. His sister, May, is \(0.18\) metres shorter than Ken. Their older brother, Leo, is \(0.25\) metres taller than May.

a) How tall is May in metres?

b) How tall is Leo in metres?

c) What is the total height of the three siblings when they stand together?

A water tank initially contained \(18.75\) litres of water. In the morning, a gardener used \(4.6\) litres to water the flowers. In the afternoon, he used \(3.85\) litres to water the vegetables. Finally, he added \(6.4\) litres of water from a tap back into the tank.